For most beach-goers, assessing a beach is simple. Is the sand good for castle construction? Is ice cream readily available? Is the water warm and relatively jellyfish-free? If not, no problem--there are plenty of other beaches in the sea.

But what about a truly special beach? One with unique physical features--such as sand comprised of tiny, star-shaped shells or a stunning mountain backdrop--where the water is superclean and the sand isn't in danger of vanishing because solid environmental management policies are in place? And let's not forget the opportunity to swim with dolphins, snorkel over barrier reefs and spot birds and other local wildlife.

Such havens do indeed exist. To pinpoint some of them for our annual list of the great beaches around the world, we turned to the Clean Beaches Council, a Washington, D.C.-based nonprofit organization that runs the Blue Wave beach program in the U.S.

These are people who know good beaches. Blue Wave is the domestic branch of Blue Flag, a beach and marina certification program that scrutinizes waterfronts around the world, holding them to high and complex environmental standards. Blue Flag was established by the Copenhagen, Denmark-based Foundation for Environmental Education in 1987.

The U.S. has no dearth of beaches--more than 3,500 in 29 states are listed on CBC’s Web site. But, while each of us has a favorite sandy spot, just .04% of American beaches have a current Blue Flag certification (it must be renewed annually). That hasn’t hampered beach-going one bit, however: Americans make 2 billion ocean, gulf and inland beach visits annually, and beach tourism generates over $640 billion here, according to CBC statistics.

Of course, those numbers are much bigger globally. And while thousands of beaches worldwide have received the coveted Blue Flag and Blue Wave certification, and the attendant crush of publicity, some of the most unusual beaches have received no certification whatsoever.

Among those exceptional locales, which are included on our list, are places like Sedir Island in Turkey, which, legend has it, features a rare type of sand Roman leader Mark Antony had shipped in from Egypt, and Mal Pais, a Costa Rican village surrounded by great surfing waters. In the United States, Crane's Beach in Massachusetts is known for its beautiful dunes, which are carefully protected--as are the nesting piping plovers.

To formulate our list, the CBC teamed up with the U.S. Geological Survey Coastal and Watershed Studies Program in St. Petersburg, Fla. They racked their brains, and the globe, to come up with ten of the best pieces of coastline anywhere--both in the U.S. and overseas. In some cases, we listed particular beaches; in others, we included entire island ranges or marine wildlife havens. All ten were chosen for their unique geologic features, innovative management practices and progressive environmental safeguards. None of them are currently designated Blue Flag or Blue Wave, for the most part because they haven't been developed to the extent necessary for certification. We suggest you go before they are.

The grand tradition of the gap year: that glorious time between school and work when young people take an extended break to see the world, explore their options and, perhaps, get a better sense of how they want to live the rest of their lives. These days, more people facing middle age are wondering why young people should have all the fun.